Integrins are transmembrane α, β-heterodimer receptors expressed on a wide variety of cells which are involved in extracellular matrix interactions. There are eight known β (beta) subunits and 14 known α (alpha) subunits that associate with each other to give at least twenty receptors with different ligand specificities. The ligands for several of the integrins are adhesive extracellular matrix (ECM) proteins such as fibronectin, vitronectin, collagens and laminin.
It is becoming increasingly clear that the ECM influences gene expression, and changes in expression of genes encoding matrix proteins alter the composition of the ECM. Thus information flows in both directions between cells and their surrounding matrix. Integrins appear to transmit messages from the exterior to the interior of the cell, inducing various kinds of changes in gene expression. In this capacity, the integrins control cell growth, motility, differentiation, and survival. Defects in the regulation of these processes result in many medically important diseases, such as inheritable developmental disorders, defective wound repair, hematological disorders, cardiovascular diseases, immunological disorders, neurodegenerative diseases, and cancer initiation, invasion, and metastasis.
α3β1 integrins have been reported to recognize several extracellular matrix ligands, including some laminins, type IV collagen, fibronectin, and thrombospondin-1. A need exists for methods that affect the interaction of α3β1 integrin-expressing cells with their environment. The present invention fulfills this and other needs.